Solventless synthesis and optical properties of Au and Ag nanoparticles using Camellia sinensis extract

A facile bottom–up “green” synthetic route using green tea ( Camellia sinensis) extract as reducing and stabilizing agent produced gold nanoparticles and silver nanostructures in aqueous solution at ambient conditions. Colloidal systems of silver and gold nanoparticles exhibit highly efficient single photon-induced luminescence. This optical response can be manipulated by changing concentrations of metal ions and the quantity of reducing agent, which plays a crucial role in formation, growth and luminescence response of these noble-metal nanostructures.